Add the '=' action modifier that instructs tmpfiles.d to check the file
type of a path and remove objects that do not match before trying to
open or create the path.
BUG=chromium:1186405
TEST=./test/test-systemd-tmpfiles.py "$(which systemd-tmpfiles)"
Change-Id: If807dc0db427393e9e0047aba640d0d114897c26
I always found this a bit annoying.
With the patch:
$ SYSTEMD_LOG_LEVEL=debug build/udevadm test /sys/class/block/dm-1
...
Loaded timestamp for '/etc/systemd/network'.
Loaded timestamp for '/usr/lib/systemd/network'.
Parsed configuration file /usr/lib/systemd/network/99-default.link
Parsed configuration file /etc/systemd/network/10-eth0.link
Created link configuration context.
Loaded timestamp for '/etc/udev/rules.d'.
Loaded timestamp for '/usr/lib/udev/rules.d'.
...
When fuzzing, the following happens:
- we parse 'data' and produce an argv array,
- one of the items in argv is assigned to arg_host,
- the argv array is subsequently freed by strv_freep(), and arg_host has a dangling symlink.
In normal use, argv is static, so arg_host can never become a dangling pointer.
In fuzz-systemctl-parse-argv, if we repeatedly parse the same array, we
have some dangling pointers while we're in the middle of parsing. If we parse
the same array a second time, at the end all the dangling pointers will have been
replaced again. But for a short time, if parsing one of the arguments uses another
argument, we would use a dangling pointer.
Such a case occurs when we have --host=… --boot-loader-entry=help. The latter calls
acquire_bus() which uses arg_host.
I'm not particularly happy with making the code more complicated just for
fuzzing, but I think it's better to resolve this, even if the issue cannot
occur in normal invocations, than to deal with fuzzer reports.
Should fix https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=31714.
This makes the functions handle "xx/" and "xx/." as equivalent.
Moreover, now path_extract_directory() returns normalized path, that is
no redundant "/" or "/./" are contained.
This also makes path_compare() may return arbitrary integer as it now
simply pass the result of strcmp() or memcmp().
This changes the behavior of path_extract_filename/directory() when
e.g. "/." or "/./" are input. But the change should be desired.
The generic string_hash_ops_free_free hash operations vtable currently
assumes the data pointer is of type char*. There's really no reason to
assume that though, we regularly store non-string data as value in a
hashmap. Hence, to accomodate for that, use void* as pointer for the
value (and keep char* for the key, as that's what
string_hash_ops_free_free is for, after all).
This adds two things:
- A new switch --uuid is added to "udevadm trigger". If specified a
random UUID is associated with the synthettic uevent and it is printed
to stdout. It may then be used manually to match up uevents as they
propagate through the system.
- The UUID logic is now implicitly enabled if "udevadm trigger --settle"
is used, in order to wait for precisely the uevents we actually
trigger. Fallback support is kept for pre-4.13 kernels (where the
requests for trigger uevents with uuids results in EINVAL).
This is like a really strong version of Wants=, that keeps starting the
specified unit if it is ever found inactive.
This is an alternative to Restart= inside a unit, acknowledging the fact
that whether to keep restarting the unit is sometimes not a property of
the unit itself but the state of the system.
This implements a part of what #4263 requests. i.e. there's no
distinction between "always" and "opportunistic". We just dumbly
implement "always" and become active whenever we see no job queued for
an inactive unit that is supposed to be upheld.
This is similar to OnFailure= but is activated whenever a unit returns
into inactive state successfully.
I was always afraid of adding this, since it effectively allows building
loops and makes our engine Turing complete, but it pretty much already
was it was just hidden.
Given that we have per-unit ratelimits as well as an event loop global
ratelimit I feel safe to add this finally, given it actually is useful.
Fixes: #13386
This takes inspiration from PropagatesReloadTo=, but propagates
stop jobs instead of restart jobs.
This is defined based on exactly two atoms: UNIT_ATOM_PROPAGATE_STOP +
UNIT_ATOM_RETROACTIVE_STOP_ON_STOP. The former ensures that when the
unit the dependency is originating from is stopped based on user
request, we'll propagate the stop job to the target unit, too. In
addition, when the originating unit suddenly stops from external causes
the stopping is propagated too. Note that this does *not* include the
UNIT_ATOM_CANNOT_BE_ACTIVE_WITHOUT atom (which is used by BoundBy=),
i.e. this dependency is purely about propagating "edges" and not
"levels", i.e. it's about propagating specific events, instead of
continious states.
This is supposed to be useful for dependencies between .mount units and
their backing .device units. So far we either placed a BindsTo= or
Requires= dependency between them. The former gave a very clear binding
of the to units together, however was problematic if users establish
mounnts manually with different block device sources than our
configuration defines, as we there might come to the conclusion that the
backing device was absent and thus we need to umount again what the user
mounted. By combining Requires= with the new StopPropagatedFrom= (i.e.
the inverse PropagateStopTo=) we can get behaviour that matches BindsTo=
in every single atom but one: UNIT_ATOM_CANNOT_BE_ACTIVE_WITHOUT is
absent, and hence the level-triggered logic doesn't apply.
Replaces: #11340
Let's add an implicit reverse dep OnFailureOf=. This is exposed via the
bus to make things more debuggable: you can now ask systemd for which
units a specific unit is the failure handler.
OnFailure= was the only dependency type that had no inverse, this fixes
that.
Now that deps are a bit cheaper, it should be OK to add deps that only
serve debug purposes.
The slice a unit is assigned to is currently a UnitRef reference. Let's
turn it into a proper dependency, to simplify and clean up code a bit.
Now that new dep types are cheaper, deps should generally be preferable
over everything else, if the concept applies.
This brings one major benefit: we often have to iterate through all unit
a slice contains. So far we iterated through all Before= dependencies of
the slice unit to achieve that, filtering out unrelated units, and
taking benefit of the fact that slice units are implicitly ordered
Before= the units they contain. By making Slice= a proper dependency,
and having an accompanying SliceOf= dependency type, this is much
simpler and nicer as we can directly enumerate the units a slice
contains.
The forward dependency is actually called InSlice internally, since we
already used the UNIT_SLICE name as UnitType field. However, since we
don't intend to expose the dependency to users as dep anyway (we already
have the regular Slice D-Bus property for this) this shouldn't matter.
The SliceOf= implicit dependency type (the erverse of Slice=/InSlice=)
is exported over the bus, to make things a bit nicer to debug and
discoverable.
These macros will log a message at the specified level only the first time
they are called. On all later calls, if the specified level is debug, the
logs will be suppressed; otherwise the message will be logged at debug.